Plasma urea appearance rate is lower when children with kwashiorkor and infection are fed egg white-tryptophan rather than milk protein

In kwashiorkor, there is less endogenous proteolysis in response to acute i nfection than in a well-nourished state. Thus the amino acid composition of dietary protein may be more important in facilitating the acute phase resp onse in kwashiorkor. This study tested the hypothesis that during the treat ment of kwashiorkor with infection, there is a lower rate of urea appearanc e when the dietary intake of amino acids more closely resembles the amino a cid composition of acute phase proteins. Thirty children in Malawi with kwa shiorkor and acute infection were fed isoenergetic, isonitrogenous meals co ntaining either egg white-tryptophan or milk as a protein source. After 24 h, the rates of urea appearance and whole-body protein breakdown and synthe sis were measured with the use of 1-C-13-leucine and N-15(2)-urea tracers. Plasma concentrations of seven acute phase proteins, interleukin 6 and tumo r necrosis factor-alpha were measured on admission, and at 24 and 48 h. The 16 children who received egg white-tryptophan had lower rates of urea appe arance than those who received milk [57 +/- 30 vs. 87 +/- 36 mu mol/(kg . h ), mean +/- SD, P < 0.02]. No significant differences were found in the rat es of whole-body protein turnover or in the concentration of any of the acu te phase proteins or cytokines. The concentration of interleukin 6 was cons istent with an appropriate proinflammatory response and correlated directly with the concentrations of C-reactive protein (r = 0.67, P < 0.01) and alp ha(1)-antitrypsin (r = 0.40, P < 0.05). The findings suggest that egg white -tryptophan is associated with less amino acid oxidation in kwashiorkor and acute infection than is milk.